A nickname for Dr. Derek Shepard (played by Patrick Dempsey) from "Grey's Anatomy." This is a very overused, shallow nickname the pathetic, hopelessly desperate main character Meredith (played by Ellen Pompeo) gives him from the beginning of the show. Of course, Mcdreamy is married and he doesn't tell her this even though they date. Anywho, any chick fan of Grey's watches the show only for him, which quite frankly makes me wanna hurl.

Meredith: Izzie, is something wrong?
Izzie: You know, I don't get special treatment just for sleeping with my boss.
Meredith: Excuse me?
Izzie: Apparently, you can satisfy Mcdreamy the way the rest of us can't.